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Re: "adapter resource shortage"?

On Tue, 5 Mar 2013, Mouse wrote:

I recently started trying to run a Sun Fire X4100, with amd64 5.2.
sd1(mpt0:0:1:0): adapter resource shortage

appearing once a second on the console (sd1 is the drive I was copying
to, the one mounted -o async; the OS is on sd0).  These stopped when
the transfer finished; when I told it to sync, in preparation for
unmounting, they started again, and, watching the disk's busy light, I
would estimate it is busy between 1/3 and 1/2 the time with a cycle
time of about 1Hz, which is cripplingly inefficient.

Reading the code leads me to suspect this is a perfectly normal
resource shortage in the presence of more transfers pending than the
hardware can handle.  However, arguing against this are (a) that
someone felt that message worth printing and (b) that the recovery
mechanism is a huge performance-killer, apparently locking up all
transfers to that drive for an entire second.  (At least, that's what
the code appears to be doing, and it matches well enough with the
behaviour I saw.)

This could be caused by the driver not reserving enough command slots for its internal use. I committed a fix to reduce the maximum commands the scsipi layer would try to use (rev 1.17 of src/sys/dev/ic/mpt_netbsd.c, which should be in the 5.2 branch). You might want to try reducing the scsipi openings a couple more and see if that helps.


Michael L. Hitch              
Operations Consulting,  Information Technology Center
Montana State University, Bozeman, MT     USA

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